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So I will I will just
start my talk right now without any
without any slides, and so who knows
about side channel attacks,
so many people and who of
us already picked a mechanical lock here
at three three?
So not so many.
This is basically also a form of a side
channel attack.
So when you pick a mechanical lock or
when you open the mechanical safe by
listening to the clicks of the lock
or by fiddling with the where you have to
push the pins down, then you use
the side channel of the sound
in the case of a safe box or
as a side channel of your feeling
in your hand to get all the pins
down.
And this is a very similar principles
that we apply to embedded devices
in in our research, and I
say our research because this has been,
yeah, work with quite so many people
actually. Like if if we had
slides, then I could, I could show
it to you.
So.
So we, of course, do not listen to
the mechanical sound of an electronic
device like a chip, although this has
been in the media, I think a couple
of days ago.
So this story by Sharma has
anybody read us said
or also many people, the story is
actually over 10 years old,
but somehow, magically it reappeared.
I don't know how it happened and
what what we use in our our
research is usually the power consumption
of the electromagnetic emanation of
of a chip.
So you can imagine if if a
transistor switches inside a processor,
inside a microcontroller, inside an FPGA
or wherever, you
always have some small variation
of the power consumption or ZM, Signal
also whizzes.
And this is the rationale behind
all side channel attacks, basically that
you can detect as very small changes
and that you then can,
yeah, extract secret keys.
Was it in the simple case you just read
off a secret key?
So thinking of
RSA algorithm, for instance, I think
everybody's familiar with said what
the basic operation is there is
you do a lot of squaring and
multiplications, right?
And depending on whether a key build is
set when you generate a signature, for
instance, you do is a multiplier
or multiply and a square operation.
So multiply operation
on an on a process has
a different power consumption, then
send a squaring operation.
So in the simple case, when the device
unprotected, you simply see, OK, the
power consumption is higher here, lower
here. So I will have
multiply it in the square, which means
the keyboard is set to one.
And otherwise you have
just the square operation and you know,
it was two zero and this was actually
also houses. The text were
or became popular in the
academic world, let's say.
So actually, I had on
my first slide, it's a small logo and
it's a free year.
But now I go back a bit to NSA also.
They had a back in Z.
I think back in the day we
need presentation slides.
Maybe I have a USB.
Yeah, sure.
So I'll speak on from down here
for full action.
So it was the NSA initially or
American Census tampers program as it
tried to read for this bulky old cipher
machine presses that were were
done from a distance or read your screen
from a distance through a wall.
And this is the first instance of a side
channel attack in this case.
But in academia, it became like popular,
starting in roundabout
ninety six.
So then some biology student
Paul Kocher, actually, he had his
oscilloscope connected to back then
banking cards and could really performs.
Is this a text
and read of the secret key?
And now, oh, we're good
to go.
Great. So, yeah, let's
have a fun.
So it was good that we had this plan
problem here. Was, of course, on purpose,
and now I can skip over all the slides.
There are of no importance anywhere.
So this are the people I've been.
I've been working with quite some long
list during the past few years
and this introduction already gave
where right now here and keeps
this map layout in place.
It has some meaning for the presentation
and beautiful book is here where this
is based, where all the
research about 18 security
is done in Belgium looks
like this. As I said, very beautiful on a
non rainy day
and both met some
problems in the past.
While Nokia was based in Belgium
and they left Balkans, they are almost
bankrupt now, went
to Romania and closed it down since then.
So we have this
loss. This industry open will also
close down very soon,
so we have to do something new and
Balkan, which is ideal security and there
is with with this guy comes
into play and also small companies
that I founded together with Timor,
which is called Casben Oswald or short
course.
As you could see in the introduction
this hour and you said here is that you
are ready for the mini chameleon
until you see that we actually build it
and that it actually works.
I tested it successfully already with the
hotel lock here and.
So.
And as I said, we have
or come into a side channel attacks, we
have embedded systems everywhere.
Is this where such an attack usually
makes sense? This BGP thing, which
mirrors kind of an exception
that you perform such an attack on
a PC, usually you target embedded
devices.
So is this my protagonist for
the presentation?
It's a typical pirate.
I took him for no reason
because pirates are cool, and
she has the typical hat, eyepatch peg leg
and the laughter.
By the way, on this most graphics
that look like this, I painted them in Ms
Paint with sand.
Not all of them.
So by the Pirate, of course, lives in the
modern world, for instance, he has his TV
set connected to some set top box, or
maybe that's already built in.
Inside, you'll find FPGA
or reprogramable logic chips.
Yes, of course, a treasure chest like
every good pirate, but it's not locked in
a mechanical way, but with an electronic
lock. So you need some electronic token
that sends radio signals out to unlock
the chest and inside of some
microcontroller that does all the
cryptographic operations necessary.
Yes, of course, computer likes this
beautiful netbook says.
And so working so fine and to lock
in. He doesn't use this password only,
but a one time password token.
Also like this YubiKey.
And this will actually be the
three examples for this presentation I'm
going to talk about.
I hope I managed to fit it into
the times that has reduced a bit more
now.
So as this important circle of its
security puts a beaver that
I obviously did not paint myself
as the constructive side of it security
because this is the nature's engineer,
you know, and the hacker is
a pirate on the other side.
And there's the very important circles
that the hacker analyzes.
Real world products reports the
flaw to the developer,
and he can then improve and in a
continuous cycle, more secure
products for for a modern world.
So this already
explained a bit sideshow analytics that
work like in a bank robbery when you have
a side channel of sound and nowadays use
side channel of emanation
or power consumption.
And of course, you don't use a stitch
scope but an oscilloscope
to attack a cryptographic socket, for
instance. And this is like this, for
instance, such an electromagnetic probe
to records the emanations.
This again, shows what I also
explained. Depending on the data you
process, the power consumption
varies a tiny bit as one clock cycle
of an atom figure here, and depending
on if all bets bits are set
or all are set to zero.
You have a different power consumption
here.
This is example for the hours
where you can directly read of the key,
which was the first instance of a side
channel attack, actually.
So usually we use
another technique because our
example works fine for algorithms like
RSA, which involve multiplications and
square rings.
But for Blocks Cipher, you have a
very atomic operations and work on
a larger stage usually.
And this is where differential power
analysis comes into play.
It is based on a statistical
test to match the
measured side channel signal with small
key hypotheses.
So it's like brute force attack, but you
look into the cipher and then are able
to find, for instance, eight bit of the
ASCII at a time because you have some
side channel.
I explain it usually like this.
So this is from the comics about the
Higgs boson, how it was detected.
So you have basically two options.
There is no Higgs boson or there was the
Higgs boson, and there is a tiny, tiny
difference between these two hypotheses.
And to detect this hypothesis,
which in our case is no Higgs boson,
it's the wrong key candidate.
Or yes, Higgs boson is the correct
candidate. You need to record a lot of
measurements to average out the noise
and then try to find the small
difference.
He says. You need a huge amount of data
for our case. It varies a bit between
100 measurements and millions of
measurements, depending on whether you
look at a modern smartcard or a simple
microcontroller.
Yes, so sorry about this speed
with this introduction, but I want to
come to practice.
And for this, I want to look
at three case studies and the first our
FPGA is who does not know what
an FPGA is?
Nobody wants to himself.
So I can skip the explanation here
and we start in our home part of Pokémon
Go to the go
to us is always the conference locations
where this was presented.
More precisely, choose the FPGA 2013
conference in Monterrey
and look at FPGA.
So FPGA is, as you know, reconfigurable
a hardware device, and they're used
everywhere where you need high bandwidth
or low latency.
Things like in routers, consumer products
like set top boxes, cars and
militaries. There was some video I could
not find about this huge machine
gun, which then has an FPGA.
It's a side I could not find is.
Unfortunately, the
problem was FPGA is they have a large
configuration bitstream, and this can be
usually easily copied because it's stored
externally because you cannot fit it
all into the FPGA, except for a flash
FPGA, as that also exists.
But here we look at this at pages that
have external memory, so you
have some on the PCB, you have some flash
memory and the FPGA on and on
every boot up a complete.
Figuration or bitstream is copied
into the FPGA, so obviously
it's a pirate who comes along here,
you can easily
get this bitstream and put it into
a second FPGA, for instance, or try to
reverse engineer that this is now
a product pirate chances our political
correct term for this.
He can simply copy the speedster.
Made this happen as far as I know, for
instance, to Cisco
in certain countries that the market was
taken over by us copied products.
So the solution, of course, is to encrypt
our cryptographers.
We encrypt.
So the idea ideas, you put a
cryptographic key ones at manufacturing
time in the FPGA, then encrypt
the bitstream was key, put it in
encrypted form into the external memory.
And now, without the knowledge of this
key, the adversary cannot
produce a second second
FPGA that accepts this
bitstream. And of course, you can also
not reverse engineer it.
So the security officers approach
license the secrecy of this key, of
course.
The motivation for this work was now
is that a colleague of mine,
Amir Moradi, has already analyzed
a lot of products from Xilinx, which is a
market leader. An FPGA is like
virtually all families up to the new
six series by means of the side
channel attacks and note here,
all the refugees have very analytically
still believed secure ciphers
like the ace or triple digits or so.
And the question was not what about
Atara, which has a share of, I believe,
30 percent or something in the market?
So here's the situation was a bit
different than with Xilinx because
there was no documentation altogether
available on the functioning of the
device, so it was a
complete black box to us.
They were totally undocumented mechanisms
that are used for some key derivation,
which I'll explain in a bit.
And for encryption
also. So we had to get to that first.
Fortunately, we could do that
from the design software of Altera,
which is called Quashes
Tool with Ida Pro, which probably
also all of you know here.
And the nice thing is ultra left, all
function names and odd symbols in there.
So it was,
yeah.
It was really helpful, they
simply forgot it, and my favorite is this
functions and main functions called do
some things as the original.
And so this
do something actually does this.
It takes two keys in this case
and the unencrypted bitstream, and
it outputs some files that
also can be programed into the FPGA with
six keys and encrypted bitstream.
So we had to get back both parts of that
OSes. One thing is why two keys.
So the idea behind this is
they have some key derivation in there.
So the two keys are put
in the software and on the FPGA
on programing into some function,
which actually derives the real keys
that is used for encryption.
So the idea behind this is if you can,
you need key one and two to
program certain real key into
the FPGA. So even if you get
this real key, let's say with such a low
tech or by probing or so,
you have to
inverts this function to programs the
same key again into an FPGA into
another Etheridge's to impede cloning.
So we looked at
this and found
it's constructed like this after some
weeks of reverse engineering.
So the real key is derived by taking
this key to a encrypting
it under key one.
So this should be a function that is,
of course, only works in one
way. So it should be hard to get back
from here to Q1 and Q2
is that generate a certain real key?
So is this a good option?
So we looked at it for a second.
And then if I ask like there's
no two to no, it's obviously not
because the ACARS has an
inverse function.
So you can pick any
key one and then decrypt
the real key under this
key one stars that you picked.
So actually, there are two to the power
of one on the 28 pairs that mapped to the
same same real key.
So again, the idea
behind this was not bet, but
the implementation here was surprising
to us, I would say.
But yeah.
So having done this, we
looked how the encryption is performed.
So how is this real and goes
is used to encrypt the bitstream here
for this, it turned out to use simple
as encounter mode.
So you have some, I've said,
to an incremented for every block.
You want to encrypt
a yes, encrypted under the
real key and then exiled with the
plaintext block.
So there are some issues with that, but
they're not really so severe as
it seems seems to be fine.
No, to the
idea of why we reverse engineered, all
that was to do our side channel attacks
without this information, how all the
encryption is done. A side channel attack
cannot be mounted because you need to
know what it's encrypted where.
So we did a bit more, got
all the file form and some coding, and
turned the black box into a white box and
went on with our analysis.
So is this what the set up looks
like? You have bought with the FPGA
here, our own programmer to be able to
send encrypted bits, streams or
data of our choosing
to the FPGA.
So then you have on top of oscilloscope
and the side channel signals here
are measured with this insanely
thick cable and inflexible cable.
It's better for the electrons, you
know, so it was just handy.
And here is a trigger signal that
starts. Oscilloscope starts
the measurement on the oscilloscope, but
when a pin is raised by this programmer.
So in this plot, you see what you
actually measure on the oscilloscope.
There are two curves here.
The black one is when bitstream
encrypted bitstream is put into the FPGA
and decrypted on there and not
decrypted on the FPGA.
Sorry. So the black one is when the
encryption feature is totally disabled
and the red one is when the encryption or
the encryption on the FPGA is enabled.
So you already see some
difference here. There's a higher energy
consumption altogether and zooming
in, you can actually figure out where
the Aztecs takes part.
So they're always small, small
periods that relate to this as operation.
And here from this period, we actually
want to extract a secret key.
So since I'm here was this, it
was obviously successful.
And here you can see a result of
this. So this is what
I already explained this approach
of differential power analysis that you
test small hypothesis for
the key. And here in gray, you do not
really see two hundred
fifty four curves in this case
that relates to the wrong key candidates.
And this curves at peak.
Here are the correct key
candidates with this message, you can
identify each as each
key for each spoke separately,
and with this gets the complete key.
And this two takes all together.
Three. So two thousand measurements
are we call them traces very often,
which is three hours
of playing around with the device and a
bit of off-line pre post-processing.
So result of first case study.
The full 128 bit ASCII
of psychotics tool can be extracted
with round about three hours.
And this key derivation mechanism, of
course, does not prevent the product
powered from cloning.
He can just do this
stuff with the s and another
important lesson here for a more general
perspective.
You can do a software reverse engineering
to do hardware techs.
After that, if you have a very complex
system, you can reverse engineer
parts from software if available and then
use that knowledge to attack the system.
So with this, we're done with the
FPGA story and they'll
go on because pirates do not only
FPGA but also, for instance,
a door locks.
And for this, we go up the coast a bit
to Canada.
Here, Canada identified with the beaver,
which has nothing to do with this
engineered. Just identify
it like this.
And we look at the locking system, which
is kept anonymous in this talk
for the obvious reason.
So here you have
a typical door and an electronic
locking system the user has some form
of token, can be some small hardware
device, some RFID card, whatever
he touches the to the
lock or holds it in proximity to the
lock, and then the door can be opened.
And now we look at the hardware, which
was used in this particular system here
to to realize this functionality.
In this case, there was a pretty complex
authentication protocol was L11 messages
being exchanged and we had no
clue how to what say what's
it actually meant?
So this was again the total black box.
However, we tried to turn this into
a white box, and for this we looked at
the components of the system.
We open both tokens and locks and
found a pick microcontroller here
and also custom ASICs
put there by the manufacturer.
So our first intuition was OK.
Every other cryptos in the A-Z, of
course, who would build an ASEC to
do non crypto stuff.
So we looked at this and
open it, and this is what other
people here can tell you even more
about us seeing Dmitry.
I will give a talk on very invasive
attacks, and Starbucks also
knows this stuff and so on.
You first solve
a chip to look at a silicon dye.
So we did this.
You put some acid on top
that it react.
And finally, you have the chip after
iterating this a few times.
So this is basic.
We actually then took pictures of this
is actually a 10 mega, I
think, 10000 pixel wide image stitched
from a lot of microscope
shots. It's very old device
in the gate, every technical technology.
So it's kind of a
pre FPGA where you just put the metal
ization on the laser.
And all the doping areas already given
its old two micrometers
has some mixed signal stuff for analog
stuff also, and it was pretty much
utilized, but already that we could have
sold OK.
So there's probably no crypto in one
thousand seven hundred transistors on
this very bad crypto.
Nevertheless, one master student
reverse engineered it on and off
it was.
And this is the result and what turns
out, OK, it's all some communication
logic for counting
some flipping bits and
waking up some microcontroller every five
hundred milliseconds or so.
Yeah, whatever.
We did it and looked at the other
components. This is the
ZaPik microcontroller.
And here we were fortunate that there
were no one attacks on these devices to
extract the program code because
these devices would, you have to know,
have some configuration bits that can
turn out turn off the readout
of the program code.
And this was, of course, enabled, but we
wanted to see what is inside the system.
So we went to circumvent this
looked first at the chip so you can find
a text for similar microcontrollers on
the internet.
And we found, OK, everything looks as you
would expect on the pick.
You have some memories here.
You have some analog stuff here and
particularly this area, which covers this
few bits.
So the fewest
bits. One interesting bit is somewhere
under this, under this metal.
Here we check that it's really
then microchip implemented it in a way
that can be circumvented by intel.
Things that happened.
So what you do is you open it,
you put some tape with your hand over
the memories that you don't want to
erase, like the flash.
And so you prom.
And then you put it at an angle under UV
lamp. And after a half an hour, when
enough photons have bounced under this
metal layers onto the floating gate,
then you can so suddenly
disable this without protection.
So.
So this was was
pretty useful because we could get all
the code from this pick, which is, by
the way, horrible to reverse engineer
because it has certain segmented
memories and whatever for such a small
device. But we eventually did it in
again and turned a black box
into white box the second time.
And from this resultant now, several
attacks said I want to briefly
summarize just him due to the time
that we have so good
singers, each token here had own
unique keys. So if you get out this key,
you can only duplicate one tokens.
It's like a mechanical key.
You can also easily copy it with
wax or so.
However, each lock has an installation
white key that is then used to derive
all the keys of the token based on
the idea and says installation,
white key and heavens is
key obtained once you can
visually emulate every token and
open every door in the system.
So one option was to perform
this invasive attack with UV light.
So this gives you the key, or you can
also do a side channel attack
with an M probe, which you barely
see here on top of the microcontroller.
And this takes around about 15 minutes
communicating with the the lock to
get Ötzi's installation white keys and
then walk into any door
and say or some more or worse,
some more severe attacks that are due to
the protocol design.
I cannot unfortunately explain
everything. Maybe next year
one system is the cryptography inside
what some mix of good crypto and bad
crypto. So some vendor design stuff
and the most more
severe thing were with random numbers
you will know about random number
generator.
And here was that internal values
were reused in the next protocol
run asset values that were sent out.
So you based on this
with clever mathematics, you can derive
from the text that gives you for
one gives you the key for a transparent
transponder just by interacting
with the door without being able to
open it.
So, yeah, this was pretty surprising.
Nevertheless, we
had, of course, communicated
with the vendor about this,
and I talk about this
at the end a short bit.
They could roll out a firmware update
that at least could fix this analytical
attacks that allow us to open every door
just by walking to it, talking to
it a few times.
And then, yeah, having have an
exit here, the hardware
techs are of course, difficult
to replace because you have to replace
all components and they're working
on their next product generation, which
shall contain some more secure
hardware where we then need other guys
like Dimitriou. And so,
yeah.
So is this lesson learned here?
Hardware reverse engineering can enable
mathematical attacks and also as a side
channel attacks.
And with this, we come to our final
point we go actually
to the heart of all the piracy as a
Caribbean where this conference was
really beautiful.
Raid 2013, it looks like this is
one picture we took, so
it's pretty a pretty nice place to
present research and we looked at
this device.
This is a YubiKey to who is
familiar with YubiKey and who
has one.
Yes and no worries.
And this is a two
factor authentication token.
You know about this.
In the past, everybody just was typing in
this password. Now we know this
eavesdropping on data
from all over the world.
You can have trojans on your computer and
so on you. So we want a hardware factor
in one of our smart cards.
Or is this as some as transaction
numbers to lock in?
You can have the infamous RSA token
or you can have the YubiKey
runs at this device.
We had a closed loop from our side
channel perspective.
So just to explain it very, very briefly,
the YubiKey X like a USB keyboard
to your computer so you can use it
without any drive us.
Basically, it
generates and enters one time
password every time you press a small
button on top.
And this is based on on the.
So again, a secure cipher.
I'd say so.
And on the bottom of the slide,
you enter your credentials and then you
press this button and it enters this
string of characters.
And they chose some encoding here
to make it compatible across all keyboard
layouts, so you will not find any
umlaut or so or so in
this.
So every time you press it, generate
some, some stuff.
Here's always some fixed idea, and this
part is encrypted here and then
and called it.
And what it contains is basically,
again, an ID and several
counters that are incremented every time
you press a button and in a certain way.
So all these fields are then put into an
AC and coded, as I said, and the question
is, can we get back to Mexico key?
Because this, of course, enables us to
duplicate the YubiKey again or just
duplicated in software because it
generates a string so we don't need the
hardware device for that.
Yeah. So for this, we started again
looking what is inside?
So there was a smart card chip inside or
is there a simple microcontroller?
Here's this video is from an HD
videos that you can find on YouTube on
the production.
So HD videos can also leak information
where the circuit is.
Justin's is plastic molded plastic
packet.
So we know news and which drills
a hole puts the acid.
And the result is this is looks
like some microcontroller to the
Trent eye with some memories and so on.
And we finally also found some markings
on that, says some.
Plus it probably nobody
notices, but it's in like
virtually every keyboard
or mouse or so. It's a cheap
USB microcontroller, and it has this
feature to do this keyboard emulation.
So this was what's the basic
best use tier. We did not try to read on
any program code because we do not even
know what kind of processors is Intel.
And there's no documentation on that.
So here comes the magic of side channel
attacks, who can also do an attack
without exact knowledge on the on the
hardware and without need to do that.
If you know the exact protocols which
were all open in case of the Yubico
YubiKey, which is a nice device, by the
way. It's a good open source design,
so we did both.
We tried to measure the power
consumption. Putin was a small,
hand-crafted adapter here, a measurement
resistor into the USB power supply,
and we also put in the M probe on top of
the device to make a noninvasive
attack, and this turned out to be a
better way to press this
button automatically.
We just took tin foil on the tin foil,
absorbs everything and connect
if you connect it to grounded, simulates
your fingers and press the button so you
don't have to press thousands times
manually.
And was this we took our measurements.
We found out that M Signal
gives better signals.
This is the one here.
On top of the power signal is somewhat
low pass filter through some
voltage regulators on the chip.
And here you can.
As a side channel, you can clearly see
the 10 rounds of the ace was the
10th round. Little short to
the end from Z was playing around
what we have to attack here.
And finally, words were able to get out
the full ASCII from this device and
actually seven no measurements with
some optimization.
So this is one hour of
physical access to the device to get
the AC out here.
So again, you see this gray
wrong candidates and this one was the
peak. The red one is the correct bud
actually for for a few,
for a few bytes of the key, just to
explain it.
So management
summary Again, we can extract
the key with side channel and text.
And then after that, of course, you can
impersonate the YubiKey.
Of course, any way you still need the
username and password, which reduces
also the risk. So you have two factors
also to attack.
Luckily, there was there is
an improved firmware version, so
all new devices since a few
months ship with this improved firmware
that it's not a tech move in this manner
easily anymore.
So we come already on still
fine, fine with time timeout.
So we come already to the final
part when pirates do good or responsible
disclosure.
So here comes the pirate A2Z
to the designer and informs them,
Hey, we have a problem with your
device. And preferably he does
this before, before he
publishes. Ever since this is how we
did it, by the way, pirates
can. And I was like, some Huawei pirates
can do good here.
Maybe someone is familiar with this crap.
So with a previous talk
we have, here's a number of pirates
approximate decreasing your thirty
five thousand eighteen twenty and only
17 real pirates left
in two thousand, and with this increase,
the global temperature
by almost two degrees.
So.
Yeah. Correlation is not causation.
This is a mystery, I'm just to
show that pirates can do some good.
We also did this and talked to the people
always at least six months before
we published our stuff, since it's a
bit variable due to our publication
times and so on.
So for the locking system, it was
approximately one year before actually it
got public.
And as I said, the vendor was
able to deploy a fix for this.
Most severe mathematical attacks
a terror. We talk to them six months
before they said, Yeah, it's like
this, and
it has
to be seen what happens in the future.
Then this FPGA field, it's an interesting
field how to protect.
It's all too complicated and with
you because we also talked round about
nine months before publishing it.
And as I said, there is an improved
firmware version 2.4 now
that mitigates these issues.
So come in briefly to how to mitigate
such stuff like such an honor.
Text one to show my two final
slides and then we come to your questions
so you can have a first line of defense.
That means you can put all those
classical countermeasures against side
channel attacks and implementation
attacks or invasive attacks in general.
So you can take secure smartcard
circuits which are certified
and you can modify the device on the
algorithmic level.
So put randomness inside since
the measurements are misaligned or that
they involve as a random values that
stay internal.
So who won? Who
wants information on this?
There are a lot of books and papers and
there was the press conference and there
were half of some people just do that.
And however, what I
want to strengthen is that's also the
second line of defense, which is the
system level, which you can very often
also use.
On the one hand, you can try to detect
the Texans in the back end.
So for a payment system, let's say you
could have a shadow account for logging
system you for a logging system,
you could have a log file if
the legal situation permits it and your
privacy policies.
And on the other end, you can try it
instead of. This detection tried to
minimize the impact, and this is where
key diversification comes into play.
This means give every device a unique
key, as it should be never shared keys
between devices where possible.
So and this I want to briefly,
briefly illustrate with my final slide
let's look at the YubiKey and to locking
system. So for the YubiKey, it would be
very well possible to give every token
a unique key.
And then an attacker will once, let's
say, a bridge into a corporate network
cannot simply take any key and
extract tokens and go into that
network.
But he has to repeat the attack over and
over again and talking about one
hour of physical access to such a token,
which you are likely to keep an eye on,
especially if it's important.
Yeah, it will would be very
complicated in reality, and this attack
does not scale.
On the other hand, case of the locking
system, you need 50 minutes per
extracting this system wide key,
which is of no importance and could also
be one hour or so, actually.
However, this one key allows you to
open all doors and one installation.
So here you have a text that scales.
You have to attack one door and then
get full access.
So this shows the two sides of the
coin. Oh, somewhat,
yeah. And was this the pirate ship
goes back to the Iranian
shores of boom to
bust way movements directly connection,
while some small harbor and some rivers
and anchors
anchors there.
Yeah. Two new adventures.
So thank you and
sorry for the technical problem at the
beginning.
Question.
Yeah. If.
Thank you.
Here's a question about that.
How can you be key
if you actually increase that use counter
by 700 while doing the task is
the key to any use anymore?
Or would system level rejecting
passports after that?
So it's not it's not like this.
So the YubiKey has to count as actually
it has one counter every time you power
ups the device.
This is incremental, and so this is a
permanent counter, and then it has the
second counter that goes up to two
hundred fifty six.
And only if this counter reps, you also
incrementally use the permanent
counter. So you would have an increase
maybe by three or so, by
two to three. Yeah.
So this is relatively unlikely
to be detected.
Microphone one
Yeah. You uh, you had,
uh, you had a question mark with the
other unique keys for the YubiKey.
So, uh, do you know if the
if ever YubiKey has a unique key?
Or are you unsure about this?
Or do you know that some of them have the
same key?
No, you can set it yourself.
So there is the utility where you can.
The key is right only.
So you can always set a new key, but you
will render the device useless if you
override the old key.
So everybody is free to do whatever
he once was. YubiKey So you can
perfectly set up a secure system with
that.
So you can. Default keys are random or
the default keys are,
I don't know, but they do not, and it's
probably the zero, I would say.
But I mean, if you set up your system and
you put the keys that you cannot read
into or you put a zero key into your
database and it's your fault.
So you said there's an updated firmware
now for YubiKey.
Do you know how they protect against your
attack and are you allowed to tell?
Um, I know personally,
I would rather not speak about this now.
OK, well, thanks.
Um, so you can you can
perfectly contact them.
OK, so they are very open with this, I
think.
Um, yeah.
I was just wondering, what's the reason
for that? Ninety two and uh,
one to the last slide
for what? And there was a ninety two here
in
ninety four as this is a slight no,
it's everywhere.
Really, this is
like crazy,
right?
OK. The last remark is just to use
this as exit and.
Don't forget to tweet these amazing
talk. Thank you, thank.